A single-ended, resonant power converter is described in Steigerwald U.S. Pat. No. 4,845,605, issued July 4, 1989, which patent is assigned to the instant assignee and is incorporated herein by reference. The converter of the Steigerwald patent is capable of operating at high frequencies, e.g. 1 MHz, and achieving high power densities. Furthermore, zero-voltage switching is realized by the Steigerwald converter, resulting in highly efficient converter operation.
One way to obtain multiple output voltages from a DC-to-DC power converter, such as the aforementioned single-ended, resonant converter, is to provide additional windings on the output transformer. In order to obtain regulated output voltages, however, a high degree of coupling among all transformer windings is essential. At high frequencies, tight coupling is difficult to achieve, resulting in output voltages which do not track closely. Moreover, if the main output winding is short-circuited, or if the main output winding is used to provide a variable voltage, then the auxiliary output voltages cannot be regulated because they track the main output voltage by virtue of the transformer coupling. Hence, it is desirable to provide a regulated power supply with multiple auxiliary output voltages that are independent of the main output voltage, which power converter is sufficiently simple in construction in order to be practicable for widespread applications.